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C. RINGWALD Feb. 21, 1933. FUSE Re. 18,743

2 Sheets-Sheet 1 Original Filed Dec. 23, 1927' 9 1,7 27 80 4 1 2 5" J d3,4 e41 J k--- -54 v v a a)? 2,73?

c. RQINGWALES' FUSE Re. 18,743

2 Sheets-Sheet 2 Feb. 21, 1933.

ori inal Filed Dec 23, 1927 CVflver/fi: Clarawcc Ring weld ill 177K955MOM/944 Reissued Feb. 21,1933 P dt ffl UNITED STATES PATENT OFFICECLARENCE RINGWALD, OF NORTH HAMPTON, OHIO, ASSIGNOB, BY MESNE ASSIGN-MENTS, T0 SGI-IWEI'IZER & CONRAD, INC., OF CHICAGO, ILLINOIS, ACORPORATION OF DELAWARE FUSE Original No. 1,862,317; dated June 7, 1932,Serial No. 242,137, filed December 23, 1927. Application for reissuefiledAugust 22, 1932. Serial No. 629,945.

or the current flow relatively great, other protective means are moregenerally employed. The chief reason for this distinction resides in twothings: first, the amount,

i. e., the mass of metal which will be blown, i. e., fused andvaporized, and, second, the limiting strength of the circumambientmedium, i. e., air, in the case of the usual small unfilled fuse.

Numerous schemes have been devised for increasing the distance betweenterminals when the fuse blows so as to diminish the amount, i. e., massof metal to be blown to give a certain clearance. Also various schemesof providing a surrounding envelope of a medium of higher dielectricstrength than air have been proposed. In some cases both means have beenprovided.

My invention, while it may be embodied in a fuse wherein the terminalsare separated to a greater extent upon blowing of the fusible element,is primarily concerned with the provision of a surrounding medium ofgreater strength than air and which has certain inherent beneficialeffects in the extinction of an arc and in the application of thismedium to the container so as to maintain the desired relation betweenthis substance and the active fuse element.

Where a mass of metal between two conducting terminals is vaporized, aflow of conducting electrons appears to be maintained. In the case ofmetal vapors, the conduction appears to occur very much as in the caseof solid conductors, i. e., by a flow of electrons through the-adjacentmolecules. In the case of the breakdown of air, it appears that thereare two things which conduct the current flow. First, the molecules ofgas are broken down to force electrons from their orbits, and, second, acertain amount of metal vapor is freed from the terminals. In the caseof a corona or brush discharge substantially no metal vapor is releasedand, hence, a relatively high resistance is maintained in the are. orspark. If the metal vapor can be kept from forming, or if it could beeliminated,

the air would continue to afford a fairly high resistance, even thoughit were broken down.

I have conceived the possibility of surrounding the arc with a substancewhich will initially afford a high resistance to current flow, i. e.,constitute of itself an excellent insulating medium of very highdielectric strength, and which, in conjunction with the vaporized metalof the electric arc, will tend to react to form a compound of such highresistance as to bind the electrons in unions which will resistdisruption and, hence, resist current flow with consequent stoppage ofthe arc.

Such compounds are generally disintegrated in the electric arc and,hence, if chilling can be occasioned at the same time that the compoundsare formed, or if the energy of the arc can be sufiiciently dissipatedto let these compounds cut down the flow of ourrent, the are can beextinguished in a simple and eflicacious manner.

For example, assume that when a metal vapor is formed I could combinethe metal with oxygen to form a high resistance oxide. If this reactioncould be carried on more rapidly than metal vapor could be released, itwill be possible at once to snap out an are positively and effectively.

So far, I have not found it possible in atmospheric air to providesufiiciently rapid oxidation and chilling to secure this result. lVith asuitable circumambient medium it can be done.

One difliculty with plain oxidation is the fact that the reaction offree oxygen with the usual metals is exothermic, with the result thatundesirable heat is liberated adding to the violence of the explosion,

I have conceived the possibility of liberating or releasing from asuitable compound the reagent which is to unite with the metal by meansof an endothermic reaction. This compound, as above explained, should bea high dielectric affected only by the heat of the arc and resistant ofitself to current flow.

The reagent which I have thus far employed successfully is chlorine.Chlorine reacts with metals in vapor form with great rapidity. I see noreason why other halogens should not operate equally well and shallshortly conduct experiments to deter mine the suitability of the rest ofthe halogen group. I conceive fluorine, which is more active thanchlorine, will perhaps give superior results. Bromine may also be used.

The particular substance which I have thus far successfully employed incarryin out my invention is chlorinated naphthalene, which is now foundon the market under the trade name of Halowax. It appears on the marketin various grades including a liquid and a solid or wax form.

Now in order to teach those skilled in the art how to practice myinvention, I shall describe in conjunction with the accompanyingspecific embodiments of my inven- In the drawings Fig. 1 is alongitudinal section through a simple elementary ing my invention F 2 isa similar view of a modification;

Fig. 3 is a longitudinal section of a fuse em ying my invention;

F 4 is an end view of the same with the end cap removed as though takenon the line 4-4 of Fig. 3;

Fig. 5 is an end view of the terminal as though viewed from the left ofFig". 3;

Fig. 6 is a side elevational view of the active fuse element employed inFig. 3;

F 7 is a longitudinal section of a modified embodiment of my invention;

F 8 is a plan view of the holder for the active element;

Fig. 9 is a longitudinal section view of the active element shown inFig. 7;

Fig. 10 is an end view of one of the caps of the outer shell of the fuseshown in Fig. 7;

Fig. 11 is a longitudinal sectional view of a spring operated fuseembodying my invention;

Fig. 12 is a longitudinal'sectional view of an expulsion type of fuseembodying my invention; and

Fig. 13 is a diagram illustrating the fundamental method involved in theextinguishment of an arcin accordance with my invention.

Referring now to Fig. 1, I show therein a metal fuse element 1 havingthe enlarged terminals 23 and having a link 4 of reduced cross sectionpreferably at the central part of the fuse. The link {and the adjacentportions of the fuse are contained within a form of a device embody- 7sleeve 5 which is preferably made of fiber or paper impregnated with awax-like compound which, upon being heated frees chlorine or otherhalogen for cooperation with the metallic vapor of the fuse.

Within the sleeve or tube 5 there is a filling 6 of the same wax-likematerial.

The substance which I have successfully utilized for this purpose ischlorinated naphthalene, which I am able to secure on the open marketunder the trade name of Halowax. This material looks much like parafiin,having sometimes a slightly yellowish tinge; it has a high dielectricstrength of the order of 250 'to 1000 volts per mill in small film. Itsmelting point is around 190 to 205 degrees F. Its boiling point is from610 to 650 degrees F. Its resistivity is of the order of 1500 10 ohmsper inch cube. Its specific gravity is about 1.589. When brought to theboiling, or approximately the boiling point, p

it has low viscosity and readily penetrates fibrous bodies. At allnormal temperatures and under normal conditions it is neutral andnoncorrosive in respect-to metals. It is soluble in practically allorganic solvent liquids and oils when heated therewith. It is insolublein caustic alkaline and acid solutions except those that are powerfuloxidizers. It is anhydrous and non-hygroscopic and therefore will notdraw or support a film of moisture. It is in its crystallization or inits solid form'entirely free of moisture. It is a relatively soft solid,crystalline and translucent. The chlorinated naphthalene may be se curedin various grades, but the above form is the preferred form, since thesolid form holds its shape under all normal atmospheric conditions.

The paper or fibrous sleeve 5 is boiled in the chlorinated naphthaleneto impregnate the same.

In Fig. 2 have shown the elements of a fuse in which the sleeve 5impregnated with chlorinated naphthalene is used alone, the heat of theare caused by volatilizing of the fusible link 4 driving someof the arcextinguishing substance from the impregnated walls of-the tube 5 to fillthe said tube 5 with active vapor. If desired, the ends of the tube 5may be obstructed to assist in this ac tion, or they may be completelyclosed upon the body of the fuse.

In the form shown in Fig. 1, the outer sleeve 5 may be made ofothermaterial, since the mass 6 of chlorinated naphthalene serves toperform the desired function of extinguishing the are independently ofthe evolution of any vapor or gas from the sleeve or envelope 5.

In Figs. 3 to 6 I have shown a commercial form of cartridge fuseembodying my invention. In this form the outer protective sleeve 7 ispreferably a bakelite tube or a tube of fiber impregnated with bakehteor the like. The ends of the tube 7 are threaded I as indicated at 8 and9 and in each end transverse slots 1011 are cut across the edge ormargin of said sleeve 7.

An end p ate member 12 having the disc 13 and the knife blade contact 14is seated upon the end of the sleeve 7 at each end. flanged ring 15having the inturned margin 16 embraces the edges of the disc member 13and is threaded down onto the threads 8, as shown in Fi 3.' The discmember 13 has two key members 17 and 18 adapted to enter the slots 10and 11 so as to anchor the knife blade member 14 rigidly inpredetermined alignment. The construction of the sleeve 7 and of theterminal members cooperating therewith is identical at each end. Theactive element within the outer shell comprises a sleeve 20 preferablymade of paper or fiber impregnated with chlorinated naphthalene of thecharacter above described. A pair of discs 21 and 22 cover the ends ofthe sleeve 20 and these discs are slotted to receivethe fusible element1 having the reduced cross section link 4. The ends of the fuse 1 extendthrough the discs 21 and 22 and are clinched or bent over as shown inFig. 4. For the purpose of equalizing the bearing of the disc member 13against said clinched end, the end of the fusible element 1 ispreferably split and the two ends are bent over in o osite directions asindicated at 23 and 24 in ig. 4. It can now'be seen that the renewableelement shown in Fig. 6 may be inserted inside the outer sleeve 7, theflanged ring 15 and the terminal element 12 being removed. The clinchedends 2324 bear against the disc or plate portion 13 of theterminalelement 12 at each end, and when the ring 15 is screwed down contact isthereby made between said ends of the fuse and the knife blade terminals1414.

In Figs. 7 to 10 I have illustrated a cartridge form of fuse withrenewable element more particularly adapted for larger capacities. Inthis form I provide an outer casing 25 from which the knife bladeterminals 26-26 project. The outer casing 25 comprises a sleeve 27preferably made of bakelite or bakelized fiber having its ends threadedto receive the caps 2828, these caps being threaded to cooperate withthe ends of the tube 27. The caps 2828 contain central slotted discmembers 2929 having a slot r 30' therethrough for receiving the knifeblade terminals 26-26. These slotted discs 29 are rotatable in the capmembers 28-28. The cap members 28 may be of metal or they may be ofbakelite or bakelized fiber or the like.

While both discs 29-29 are herein shown as rotatable, obviously one ofthem may be anchored and be non-rotatable with respect to its cap 28 ifso desired. Also it will be apparent that if desired the caps 28 may beformed into the shape of flanged rings only,

as shown in Fig. 3, and the discs 2929 extended out to rest upon theends of the sleeve 27 is so desired. The knife blade terminals 2626extend inwardly towards each other at their inner ends, and these 'innerends are shaped to form semi-cylindrical sockets to receive a cradlemember 30 which is preferis enlarged to form shoulders 3333 for limitingthe endwise motion of the cradle in the outer casing 25.

These shank members are also provided with threaded openings 3434 forreceiving clamping screws 35, the said clamping screws being adapted topass through holes 3636 in the ends of the active element shown in Fig.9. The renewable element comprises the fuse 1 preferably having link ofreduced cross-section 4 enclosed in an outer shell or casing 37 havingend caps 38-38.

The end caps and the shell 37 may be made of paper or fiber impregnatedwith chlorinated naphthalene, and the said fuse element 1 supported insaid end caps, which are in turn connected together to the end sleeve37. If desired a filling 38' of the solid wax-like chlorinatednaphthalene may be employed within the sleeve 37.

For the renewal of the active fuse element, the renewable member isreleased at the screws 3535 and a new element dropped into theecradleshown in Fig. 8, whereupon the endslof the fuse 1 are clamped by thescrews;35,.; then one end or knife blade terminal 26-is passed through aslot in the disc 29, then the cap at the opposite end with its disc 29is passedover the adjacent knife blade contact 26 and the cap member 28is screwed up tight on the outer sleeve 27 In Fig. 11 I have shown afuse in which the fuse terminals are separated by means of a sprin whenthe fuse element melts. In this case provide an outer container formedof a piece of glass tubing 41 which has a cap 42 preferably of brasscemented upon the lower end of the same or otherwise suitably securedthereto, and a sleeve or ferrule 43 cemented or otherwise secured to theupper end thereof. The sleeve 43 extends be' tral arched portion 46 ispulled downwardly, tending to spread the edges of the disc into the sideengagement with the counterbore of the ferrule 43.

The fuse element comprises a link 48 preferably having a smallcross-section at the point where the blowing is to occur, and connectedtosuitable metallic terminals 49 and 50. These terminals and the fuseelement are imbedded in a mass or filling 51 of chl'orinated naphthalenein Wax form, said filling being contained within a sleeve 52 formed offiber or paper impregnated with the same substance. The terminal 50 isconnected to the sleeve 52 by a transverse pin 53 extending through bothof said elements. The spring 47 is secured to the lower end of theterminal member 50 and to an anchor 54 formed on the cap member 42. Thespring 47 is placed in tension and the upper terminal member 49 ispassed through an opening in the cap member 46 and is there anchored asb soldering or by forming a button or the like upon the end of theterminal 49 which is then drawn down tight into engagement with theedges of the hole formed in the cap member 44.

It is not essential that the casing be absolutely fluid tight, but it isdesirable that it be so to the extent of excluding moisture.

Upon blowing of the fusible portion 48, the arc extinguishing material,i. e., the chlorinated naphthalene, is immediately available to attackthe substance of the arc and form with it non-conducting compounds,which, being chilled by the presence of the mass of material and thesleeve outside of the same, becomes a non-conductor of electricity. Atthe same time, the terminals are separated to increase the length of thearc and, hence, its vulnerability to attack. The sleeve 52 with itsfilling 51 of chlorinated naphthalene is drawn down with the spring 47so that the 'movable terminal 50 is surrounded by a bath or mass of thechlorinated naphthalene regardless of the position of the fuse.

Obviously, the upper end of the sleeve 52 might be attached to the capmember 44, and the terminal 50 pulled down through the mass of arcextinguishing material, but this would expose the glass sleeve 41 to theheat of the arc directly, and that is not desirable.

To avoid exposing the upper end of the glass sleeve to the heat of thearc, I provide a sleeve or lining 56 of paper or fiber impregnated withchlorinated naphthalene at the upper end of the glasssleeve where theglass might be exposed to the are by a downward movement of the movablesleeve 52.

'If the arc persists until one of the terminals ber 56 is acted upon bythe arc to evolve gaseous arc extinguishing medium therefrom which tendsto fill the space occupied by the arc. If the cap 44 has been blown off,the gaseous medium sweeps endwise out of both the tubular members 52 and56 to atmosphere.

Obviously, as soon as the tension of the spring leaves the disc 44, itstendency to bind the counterbore of the ferrule 43 is reduced, and anytendency to form high pressure within the outer casing 40 will result inblowing off the cap or disc 44 and relieving the pressure.

The fuse may be refilled by supplying a new terminal 50 and attachedsleeve 52 and filling 51 with the fusible element 48 and terminal 49.Preferably the spring 47 is shunted by a flexible conductor.

In Fig. 12 I have shown an expulsion type of fuse embodying myinvention. In this y case I employ a sleeve of insulation as shown at57, this sleeve being formed of bakelized fiber, porcelain or glass. Tothe lower end of the sleeve 57 there is attached a ferrule 58 with aterminal screw 59 for clamping the lower end 60 of the flexible fuseterminal 61 to the ferrule 58. To the upper end of the sleeve 57 Iconnect an explosion chamber member 62. This is preferably formed of ametal casing cemented or otherwise secured upon the upper end of thesleeve 57 and having a threaded opening at its upper end in alignmentwith the bore of the tube 57 and normally closed by a threaded plug 63.To the threaded plug 63 on its lower end I connect a fuse terminal 64,and between the fuse terminal 64 and the fuse terminal 61 a fusible link65 is connected. On the outside of the lower end of the terminal 64 andthe upper end of the terminal 61 I mount a sleeve 66 of paperimpregnated with and filled with a mas; of chlorinated naphthalene asindicated at 6 Upon blowing of the active element 65 the are which isformed is immediately attacked by the arc extinguishing material insolid form, which, by the heat of the arc, is melted and vaporized tosome extent. The pressure which results from the formation of the arcexpels or in part expels the paper sleeve 66 with its filling 67 ofwax-like arc extinguishing material. If the exploson is particularly.violent the entire sleeve with its mass of material and the terminal 61may be expelled through the sleeve 57.

The fuse may be refilled by removal of the threaded plug 63 andloosening of the terminal 59 to release the portion 60 of the fiexibleterminal and an entirely new fuse and terminal attached to a plug suchas 63, dropped down through the open end of the chamber 62, anddown-through the sleeve 57. The upper-terminal 64 may be fixedly securedto the plug 63 or releasably secured to the same, this feature beingoptional.

In all of the forms illustrated, the arc is brought into contact with amass of chlorinated naphthalene preferably in the solid form. Obviouslywithin any invention the liquid form may be employed, care being takento make the container sufficiently tight to retain the liquid form. Thecontact of the heat of the arc with the chlorinated naphthalenedissociates and the halogen element 'thereof attacks the metal vapor ofthe arc, forming non-conducting compounds which, being chilled andstabilized by the surrounding: relatively cold mass, do not furtherdisintegrate under the electric arc, with the result that the fuseeffectually prevents sustained current flow;

To illustrate the fundamental action involved, I show in Fig. 13diagrammatically two metallic terminals and 71 between which an arc isformed within the sleeve or housing 72 by current supplied through asuitable source as indicated at 73. An inlet nozzle 74. is directed intothe space in which the arc is formed and this is connected by a pipe 75through a control valve 76 with a tank of chlorine gas under highpressure, as indicated at 77. Assume that the arc is formed between theterminals 70 and 71 in a relatively confined space. I thereupon admit athigh velocity and at relatively high pressure chlorine gas whichdisplaces the'atmospheric air tending, by its chilling effect, to reducethe temperature within the container 7 2 and tending, by its chemicaleffect, to combine with the metal which is in extremely susceptible formto chemical action, whereby non-conducting compounds are formed fasterthan metal can be liberated from the terminals 70 and 71, with theresult that the arc is extinguished.

It will be seen that it is desirable to employ as an active element amaterial which will have the ability to attack the active metal or otherconducting substance in the are at a temperature less than thetemperature of the electric arc and with great rapidity.

Preferably such action should not add heat to the mass, but shouldrequire a temperature less than the temperature of the are for its bestor optimum condition. The chlorinated naphthalene requires heat to breakit down to free the chlorine, and this, therefore, forms an idealcombination, since the reaction is endothermic to the extent ofrequiring the heat of the arc to liberate the chlorine, which chlorinein turn attacks the arc to form a compound which is non-conducting, orrelatively so, and which, due to the extraction of heat therefrom,becomes stabilized and will not again dissociate. I

I do not intend to be limited to the details shown and described. nor tothe specific material which I have above described in detail,

since I am convinced by my experiments that fluorine, as an activeelement, would be even more effective for this purpose.

It may be that other negative elements or radicals combining with themetal of the fuse will be equally effective in forming a non-conductingcompound to extinguish the arc, and these, if discovered, I beg toinsert in this description hereafter as coming within the broad scope ofmy invention.

Preferably the metals which I employ for the fusible link are such asaluminum, zinc, tin and lead, which are very quickly attacked by thehalogen group, but I do not wish to confine myself to these metals,since, at the heat of the electric are, all of the ordinary baser metalscombine readily with the more active halogens.

1. In a fuse device, the combination of a container comprising an outersleeve of condensation product and an inner lining of fiber impregnatedin a solid waxy halogen derivative of naphthalene, and a fusible linkwithin said container.

2. In combination, an outer sleeve having a metallic cap at one end, ametallic ferrule at the other, said ferrule having a portion extendingbeyond the end of the sleeve, a removable closure for said end of theferrule, a spring secured to the cap within the sleeve, a pair ofterminals, one of which is connect ed to the spring, the other of whichis connected to the ferrule, a fusible link between said terminals and afilling of solid arc extinguishing material surrounding said fusiblelink, said material being converted from solid to liquid and from liquidto gas by absorption of theheat of the are formed when said linkruptures to quench that are.

3. In combination, an outer sleeve having a metallic cap at one end, ametallic ferrule at the other, said ferrule having a portion extendingbeyond the end of the sleeve, a removable closure for said end of theferrule, a spring secured to the cap within the sleeve, a pair ofterminals, one of which is connected to the spring, the other of whichis connected to the ferrule, a fusible link between said terminals and afilling of solid arc extinguishing material surrounding said fusiblelink, an inner sleeve for containing said solid mass of arcextinguishing material, said inner sleeve being connected to the springand movable thereby together with the movable terminal, and a thirdsleeve impregnated in said are extinguishing material and interposedbetween said inner and outer sleeves to protect the latter from rupturewhen said link is ruptured.

4. In combination, an outer sleeve element, closure members for eachendof the sleeve, a pair of terminal members electrically connected to eachof the closure members, one of said terminal members being movable, a

ing of a fusible member encased in a filling of chlorinated naphthaleneand having terminal members projecting from said cartridge,

a mounting therefor consisting of a cup-like body conforming to thecontour of said cartridge with terminal pieces projecting from oppositeends of the body, to which pieces said cartridge terminal members areattached, and a casing surrounding said cartridge and body, from whichcasing said terminal pieces project.

6. In combination with a fuse cartridge having a fusible member whosemiddle portion is encased in a body of chlorinated naphthalene and whoseend portions form terminals projecting therefrom, a mounting comprisingknife blade terminal members spaced apart by a cradle in which saidcartridge rests, means for fastening said terminals to said knife blademembers, and means removably supported on said members for encasing saidcartridge and cradle.

7. In combination with afuse cartridge having a fusible member whosemiddle portion is encased in a body ofchlorinated naphthalene and whoseend portions form terminals projecting therefrom, a mounting comprisingknife blade terminal members spaced apart by an insulating cradle inwhich said cartridge rests, means for fastening said terminals to saidknife blade members, and

means removably supported on said members for encasing said cartridgeand cradle.

8. In combination with a fuse cartridge having a fusible member whosemiddle portion is encased in a cylindrical body of chlorinatednaphthalene and whose end portions form terminals projecting therefrom,a mounting comprising knife blade terminal members spaced apart by asemi-cylindrical insulating cradle in which said cartridge rests, meansfor fastening said terminals to said knife blade members, and meansremovably supported on said members for encasing said cartridge andcradle.

9. As an article of manufacture, a fuse comprislng a casing havingremovable ends,

contact strips extending from said ends, an

insulating cradle within said casing supported on the inner ends of saidcontact strips, and a fuse cartridge supported in said cradle and havingterminals electrically connected to said contact strips.

10. In combination with a fusible metal encased in a body of chlorinatednaphthalene and projecting from the ends thereof, an open end insulatingtube into which said body fits, a metal expulsion chamber attached toone end of said tube, a plug attached to one of the projecting parts ofsaid fuse and threaded into said chamber to close it, 2. metal ferruleattached to the outside of the other end of said tube, and means forattaching the other of said projecting ends of the fuse to said ferrulewithout closing the end of said tube to thereby permit the pressureformed by an arc in said naphthalene to expel said body from, the tube.

11. In an expulsion type fuse, an insulating tube, a metal expulsionchamber attached toone end of said tube, said chamber having a threadedopening opposite the end of said tube, a metal band or ferruleencircling the other end of said'tube, a fuse cartridge comprising afusible strip encased in a body of chlorinated naphthalene, a threadedplug attached to one end of said strip, said plug being threadedintosaid opening to close the expulsion chamber when said cartridge is inplace, and a contact strip attached to said fusible strip and ferrule,said strip leaving the end of the tube open to permit expulsion of thenaphthalene body by the gases formed therein by the fusing of saidfusible strip. 12. In an expulsion fuse, an outer tube with an expulsionchamber attached at one end thereof, a ring or ferrule encircling theother end of said tube, a fusible element attached to said ferrule andchamber, an inner tube loosely fitted in said outer tube and surroundingthat portion of the fusible element within said chamber, and a fillerwithin said inner tube and around said fusible member, said filler beingvolatilized by the are formed by the fusing of said element to form anarc quenching gas, the pressure of which expels said inner tube fromsaid chamber through said outer tube to thereby separate the ends ofsaid fusible element to expedite the extinction of said are by said gas.

13. In an expulsion fuse having an expulsion chamber closed at one endby'a removable plug, an open ended tube extending from said chamber, afuse cartridgein said chamber, a connectionbetween one end of said fusecartridge and said plug, a ferrule surrounding the open end of saidtube, a connection between the opposite end of said cartridge and saidferrule, and means within said cartridge acted upon by the are caused bythe fusing of said fuse to form an arc quenching gas the pressure ofwhich expels said cartridge from said chamber through said tube.

14. In combination, a fuse casing comprising a sleeve of insulationhaving encircling external terminals mounted upon the ends thereof, afuse within said casing adjacent one end thereof for connecting saidterminals, means connecting said fuse to said external terminals, saidmeans including a rodlike terminal, and an elongated body of a solidcrystalline material surrounding one end of said fuse and said rodliketerminal, said body lying within the bore of said one end of the sleeveand being adapted under the action of the are formed upon blowing of thefuse to evolve a fluid having high are extinguishing properties, saidrodlike terminal being free to move toward the other end of the sleevefor lengthening the arc and thereby to bring more of the arcextinguishing material Within the influence of the arc.

15. In combination, a fuse casing comprising a sleeve of insulationhaving encircling metallic members mounted upon its ends formingexternal electrical terminals, a fusible link Within and adjacent oneend of said casing, a body of solid crystalline compound surroundingsaid link and extending a substantial distance beyond one end thereofand toward the other end of the casing, a rodlike metallic internalterminal extending through a portion of said body and being connected tothe adjacent end of the fuse, said internal terminal having electricalconnection with the external terminal at the other end of the casing andbeing movable upon blowing of the fuse toward said other end of thecas-' ing to lengthen the arc, and to extend its influence upon saidcompound, said compound being resolved by the heat of the are formedupon blowing of the fuse to liberate a gaseous medium effective toextinguish the arc.

16. In combination, a fuse casing comprising a tube of insulatingmaterial, external terminals fixed on the tube, a pair of internalterminals connected to the external terminals, a fusible link betweenthe internal terminals, one of said internal terminals being movableaway from the other internal terminal upon melting ofthe fuse link,means for automatically separating said terminals upon'melting of thefusible link, and a selfsustaining body of solid arc extinguishingmaterial having a bore within which the arc is drawn by separation ofsaid internal terminals, said are extinguishing material being heated bythe arc to liberate an arc extinguishin g fluid in said bore.

17 In combination, a fuse casing comprising a sleeve ofv insulationhaying metallic members upon the ends thereof forming external circuitterminals. a fusible link withi n said casing, a self-sustaining body ofa solid are extinguishing material substantiallv filling the bore of apart of the casing and surrounding the fuse, said solid arcextinguishing material being affected by the heat of the arc to liberatean arc extinguishing medium of great effectiveness, a metallic fuseterminal extending through a part of said body of arc extinguishingmaterial and being connected to an adjacent end of thefuse, theremainder of the bore of the tube being free to. permit retraction ofsaid fuse terminal upon blowing of the fuse, and a spring for retractingsaid terminal to lengthen the arc and bring a greater part of said bodyof arc extinguishing material within the influence of said arc.

18. In combination, a fuse casing comprising a sleeve of insuationhaving metallic members upon the ends thereof forming external circuitterminals, a fusible link within said casing, a self-sustaining body ofsolid arc extinguishing material substantially filling the bore of apart of the casing and -surrounding the fuse, said solid arcextinguishing material being affected by the heat of the arc to liberatean arc extinguishing fluid of great effectiveness, a metallic fuseterminal ertending through part of said body of material and beingconnected to an adjacent end of the fuse, the remainder of the bore ofthe tube being free to permit retraction of said fuse terminal uponblowing of the fuse, and a spring for moving said terminal to lengthenthe are within said body of material, said terminal being drawn throughthe body of material whereby the arc'acts upon a greater part of thebody of material and is subjected to greater arc extinguishing action atthe same time that its length is increased.

19. In combination, a pair of terminals, a fuse connected between saidterminals, a selfsustaining body of solid arc extinguishing materialdisposed adjacent the fuse and adapted when subjected to the arc toevolve an arc extinguishing medium, and means for separating saidterminals upon blowing of the fuse.

20. In combination, a fuse casing, a fuse in the casing, a surroundingtubular body of self-sustaining solid arc extinguishing materialdefining a fuse chamber, said material being adapted, under theinfluence of the arc, to evolve a gaseous are extinguishing medium, andan adjacent chamber communicating with the fuse chamber and into whichgaseous medium evolved from the body of material is adapted to beprojected, whereby the motion of the gaseous medium relative to the arcis beneficial in extinguishing the are,

21. In combination, a pair of fuse terminals, a fuse between them, aspring free to separate said terminals to extend the length of an areformed upon blowing of the fuse, and an elongated self-sustaining hollowbodysurrounding the fuse and within the bore of which the arc is adaptedto be lengthened, for evolving from the inner walls thereof by the heatof the arc a gaseous arc extinguishing medium, said hollow bodyconfining and directing the flow of the'gaseous medium into the are andlongitudinally of the bore of the body.

22. In combination, a pair of terminals, a fuse connected between saidterminals a body of self-sustaining crystalline compound disposedadjacent the fuse and adapted when subjected to the heat of the arc toevolve an arc extinguishing medium means cooperating with said body todirect the arc extinguishing medium into the arc, and a spring forSeparating said terminals upon blowing of said fuse.

23. In combination, a air of terminals between which an arc is a aptedto be formed, a surrounding casing substantially embracing the arcsaid-casingcemprising, a crystalline self-sustainin solid which byaction of the arc liberates uids which have high are extinguishingproperties and constituting means to inject these fluids at highvelocity laterally into the arc, and means for separating the terminals.

24. In a'fuse, a tubular self-sustaining. solid having a bore,=the wallsof which comprise a self-sustaining surface of an arc extinguishingcompound from which, by the action of an arc, a gaseous arcextinguishing medium is evolved, fuse terminals and a fuse between, saidterminals, said fuse upon being blown forming an are within said tubularbore, said gaseous medium filling the said bore and being driven out ofone end thereof to extinguish the arc.

' 25. In a protective device of the class described, a tubular housingcomprising ferrules constitutin external terminals, a pair of internalterminals, a spring connected to one of the internal terminals forseparating. the same, a fuse connected between said internal terminals,and means for supplying a gaseous arc extinguishing medium to extinguishthe are upon blowing of the fuse, said means including a tubular memberproviding a self-sustaining surface of solid arc extinguishing materialadapted to be acted upon by the arc to release gaseous arc extinguishingmaterial and to extinguish the are upon moderate overload, and a secondtubular member of larger bore than the first tubular member adapted, inthe case of heavy overload, to be acted upon by the arc and to evolvegaseous arc extinguishingmaterial for extinguishing the 'arc therein.

26. The -method of interrupting current flow through a fuse, whichcomprises blowing the fuse to vaporize the metal of the same,

7 establishing an arc through said metallic vapor, laterally confiningthe arc, injecting a gaseous medium of relatively low arcsustaining-character into the laterally confined space occupied by saidare so long as the arc persists and thereby driving out the metallicvapor and supplanting it with said gaseous medium.

27. The method of extinguishing an arc,

which comprises laterally confining the arc, evolving a gaseous areextinguishing medium by the action of the heat of the arc, said gaseousmedium sweeping out of said laterally confined space metallic vaporsreleased by the arc and supplanting them by said gaseous medium so lonasthe arc continues.

28. The met d of extinguishing an are, which comprises laterallyconfining the arc in the presence of a deionizing agent to causeevolution of gaseous medium the pressure of which rises and creating arapid flow of said gaseous medium substantially longitudinally of thearc to drive out metal vapors and break up and deionize the arc.

29.111 a device of the class described, the combination of a fusehousing having metallic ferrules of a. tubular explosion chamber withinsaid housing, a fusible link within said housing, there'being an arcextinguishing material subject to the action of the are caused byblowing of the fuse for forming within the explosion chamber a gaseousarc extinguishing medium which sweeps out of the explosion chamber themetallic vapors of the fused link and supplants it with a medium oflower arc sustaining character. ;..30.' In a device of the classdescribed, the combination of a fuse housing having metallic ferrules ofa tubular explosion chamber within said housing, a fusible link withinsaid housing, there being an arc extinguishing material subject to theaction of the are caused by blowing of the fuse for forming within theexplosion chamber a gaseous arc extinguishing medium which sweeps out ofthe explosion chamber the metallic vapors of the fused link andsupplants it. with a medium of lower are sustaining character, and meansfor automatically'extending the length of the are upon melting of saidlink.

31. The method of interrupting current flow through an arc, whichcomprises continuously evolving by the heat of the arc an arcextinguishing medium so long as the are persists, directing said mediuminto the arc, confining a portion of said medium in contact with the areagainst movement laterally of the arc while permitting movement of themedium longitudinally of the arc to displace the conducting gasesof thearc longitudinally.

32. The method of interrupting current fiow through a fuse, whichcomprises blowa ing the fuse to vaporize the metal of the same,

establishing an are through said metallic vapor, subjecting to the heatof the are a material capable of evolving an arc extinguishing medium,continuously evolving said medium so long as the arc persists, andcreating a continuous blast of said medium longitudi-- nally of the areso long as the arc persists,

. to displace theconductive vapor of the arc longitudinally of the arc.

33. The method of interrupting current flow through a fuse, whichcomprises maintaining alongside the fuse a material capable of evolvinga aseous arc extinguishing medium when subjected to the heat of an arc,blowing the fuse to vaporize the metal of the same, establishing an arethrough said metallic vapor, evolving continuously from said material bythe heat of the are a gaseous arc extinguishing medium, and confiningsaid gaseous medium against lateral flow away from the arc whilepermitting flow of said medium longitudinally of the arc.

34. The method of interrupting current flow through a fuse, whichcomprises maintaining alongside the fuse a material capable of evolvinga gaseous arc extinguishing medium when subjected to the heat of an arc,blowing the fuse to vaporize the metal of the same, establishing an arcthrough said metallic vapor, evolving from said material by the heat ofthe arc a gaseous arc extinguishing medium, confining said gaseousmedium against lateral flow away from the arc while permitting flow ofsaid medium longitudinally of the arc, andseparating the terminals ofthe arc to extend the length of the arc to subject more of the aforesaidmaterial to the heat of the arc and thereby accelerating the evolutionof said medium and the longitudinal flow thereof.

35. The method of interrupting current flow through a fuse, whichcomprises blowing the fuse by current flow therethrough, establishing anare through the metal vapor, confining the lateral expansion of saidmetal vapor and permitting longitudinal expansion of the same,continuously absorbing the heat of the are so long as the arc persistsby an arc extinguishing material, continuously evolving from saidmaterial by said absorbed heat a gaseous arc extinguishing medium, anddirecting the gaseous arc extinguishing medium longitudinally of the arcto displace said metallic vapors of the are.

36. In combination, a fuse housing, a pair of terminals disposedtherein, a fuse connected between said terminals, are extinguishingmaterial disposed within the housing being directly exposed to the areformed upon blowing of the fuse, said material, upon blowing of the fuseand formation of an are between the terminals, being converted into agaseous arc extinguishing medium and being discharged into the arc, andtubular means within said housing, said means surrounding a part of thearc and producing a condition of higher pressure of said medium at onepoint on the length of the arc than at another, whereby flow of thegaseous arc extinguishing medium through said tubular meanslongitudinally of the arc is created and maintained so long as the arcpersists.

37 In combination, a housing, a pair of terminals therein, a fusebetween the terminals, a spring for moving one of the terminals awayfrom the other when the fuse 1s blown, a tubular body inthe housing,said body having a bore embracing a part of the arc, and a mass of arcextinguishing material, said body presenting said are extinguishingmaterial to the heat of the arc to cause said material to release an arcextinguishing medium which is directed into the arc within the bore toexpel the conducting gases of the arc longitudinally out of said bore.

38. In a protective device of the class described, a tubular housingcomprising ferrules constituting external terminals, a pair of internalterminals connected to said external terminals, a spring connected toone of the internal terminals for separating the one internal terminalfrom the other, a fuse connected'between said internal terminals, areextinguishing material within the housing, said material being subjectedto the heat of the are upon blowing of the fuse to evolve a gaseous arcextinguishing medium, and means within the tubular housing providing afirst bore of reduced diameter within which the arc is formed and asecond bore of larger diameter than the first bore into which latterbore the are is extended by movement of the movable internal terminal,the are acting upon said are extinguishing material in both said boresfor the evolution of said gaseous arc extinguishing medium so long asthe arc persists.

39. In a fuse device, a sleeve of insulation, a pair of externalterminals upon the ends of said sleeve, one of said terminals closingthe end of the sleeve, a conductor extending longitudinally through saidsleeve of insulation and connecting said terminals, said conductorcomprising a fusible link at its intermediate portion, a second sleevewithin said first sleeve surrounding said fusible link, and a mass ofsolid crystalline arc extinguishing material supported inside saidsecond sleeve, said material absorbing heat from the arc formed uponblowing of the fuse and evolving a gaseous arc extinguishing mediumwhich is confined against lateral expansion by said second sleeve, saidsecond sleeve be ing adapted to be expelled from the end of the firstsleeve by action of said gaseous medium.

In witness whereof, I hereunto subscribe my name this 18th day ofAugust, 1932.

CLARENCE RINGWALD.

